The Continuing Mystery of SIDS
Sudden infant death syndrome ( SIDS) is the greatest cause of infant deaths ranging from ages one month to one year. Most of these deaths occur before the age of six months. Normally, any unexplainable infant death is considered to be due to SIDS. Numerous attempts have been made to discover the exact cause of this syndrome. However,the only known pathology is that SIDS is due to a dysfunction or abnormality in the cardiac and/or respiratory systems. To this point, an exact and definite cause has not been named. This paper will attempt to present several of the proposed and hypothesized causes of SIDS.
First of all, it is necessary to understand some of the important features of this syndrome (Naeye, 1976). As mentioned initially, SIDS deaths occur in infants ages one month to one year. Also, 90% to 95% of these infants die during sleep, and most of these deaths are silent. One-third to one-half of the SIDS victims have been found to have a mild infection (normally respiratory in nature) prior to death. SIDS has also been found to be in part associated with a low socioeconomic status, and it is more common among non-whites. Although SIDS seems to be associated with a low socioeconomic status, SIDS is not caused by malnutrition. A more recent article also reported that more male infants were victims of SIDS than females ( Becker 361 ). Finally, SIDS has been more often associated with prematurely born infants. This seems to suggest that developmental immaturity may present a likely situation for the development of SIDS. Each of these characteristics must be considered when forming hypotheses for the possible cause of SIDS.
Initially, research on SIDS centered around the performance of an autopsy upon the infant. However, little conclusive evidence was found in these post-mortem infants.
Possible post-mortem characteristics of SIDS victims have been found to be normal in
comparison with post-mortem non-SIDS infants of the same age. Furthermore, no abnormalities in the growth and morphology of the lungs and hearts of SIDS infants have
been found. Therefore, in more recent years, research has shifted from the actual death
and autopsy findings to chronic abnormalities found within these infants prior to death.
The list of proposed chronic abnormalities is lengthy. To this date, research has confirmed the following: 1) SIDS is due to a dysfunction of the cardiac and/or respiratory systems, and 2) the death of the infant is due to hypo-ventilation of the lungs and periods of complete cessation of breathing or apnea. Hypo-ventilation and apnea cause hypo-perfusion of the tissues with necessary oxygen. Ischemia of tissues results and eventually causes death. Research now centers around discovering the cause of infant hypo-ventilation and apnea.
Hypothesized causes of SIDS generally have fallen into three basic categories:
1) causes related to the respiratory system; 2) causes related to the...